The point is that women (and people in general) should be able to wear what they want to wear without facing harassment. She lifted up her skirt to showcase the kind of comments women receive when they dress a certain type of way.
If that was her point then why didn't she dress one of those "certain ways"? Because right now her message is nebulous and she just looks like she's doing the thing embarrased little girls do with their skirts.
You're under arrest you sick freak.
Normal people who have decency don't just undress themselves in public